Blasting cartridge



Jan. 27, 1948. F. H. ARMSTRONG BLASTING CARTRIDGE Filed Nov. 28, 1945 2 Sheets-Sheet 1 Q 4 wqw WM x &\ Z I. .9 w i Z l EEE m. ,M \w\\ (N K Q w v Q a N wuw a Jan. 27; 1948. F. H. ARMSTRONG I BLASTING' CARTR-ID GE Filed Nov. 28,.1945 2 Sheets-Sheet 2 dim Patented Jan. 27, 1948 BLASTIN G CARTRIDGE Frank H. Armstrong, Chicago, Ill., assignor to Armstrong Coal Break Company, a corporation of Michigan Application November 28, 1945, Serial No. 631,303

vide an improved blasting cartridge for use in coal mines and the like, wherein the cartridge may be operated at will by a trigger device extending out of the casing, and the surrounding material may be broken loose without employing any igniting means.

A further object of the invention is to provide a blasting cartridge with an improved valve means, which will open quickly when released, with little throttling action, and which will automatically close the chamber after discharge, so as to prevent extraneous material from entering the cartridge. Other objects and advantages of the invention will be understood from the following description and the appended claims.

The invention is illustrated in a preferred em bodiment in the accompanying drawing, in which- Figure 1 is a broken longitudinal sectional view of a blasting cartridge embodying the invention; Fig. 2, a fragmentary longitudinal sectional view, taken as indicated at line 22 of Fig. 1; Fig. 3, a view similar to Fig. 1, but showing the cartridge while being discharged; Fig. 4, a vertical sectional view, taken as indicated at line 44 of Fig. 1; and Fig. 5, a sectional view taken as indicated at line 5-5 of Fig. 2.

In the embodiment illustrated a long tubular casing 6 is closed at one end by means of a threaded connection with a cap 1, through which extends a hollow trigger member 8 surrounded by packing 9 held by a stufilng gland ill. The trigger member has a conduit ll through which air may be introduced into the casing from a flexible tube l2 provided with acoupling l3. The trigger member is preferably provided with a collar-1ike stop I4, so that it maymake but a' limited travel with respect to the casing.

The casing also has a cylinder portion l5, provided with a series of laterally extending discharge ports l6, which are normally closed by a sleeve-like valve member 11, having a skirt l8. As the gas pressure in the casing may be about eleven thousand pounds per square inch, ,it is necessary that a very effective sealing meanslbe provided. To accomplish this, a thin metal sleeve I9 is gripped between a shoulder on the cylinder l5 and the threaded portion of the casing 6, as shown at 20. This member provides an annular cavity which receives the skirt Ill. The valve member II has a difierential head 2| having a 5 Claims. (01. 102-25) 2 larger area on the right, as viewed in Figs. 1 and 3, than on the left. This differential head urges the valve to open position under the infiuence of the pressure in the cartridge. The outer end of the cylinder 15 is provided with a screw plug 22 whose inner end is bifurcated at 23 to receive a pairoi locking dogs 24, which have beveled ends 25, to engage the chamfered end of the valve member II. The locking members are yieldingly urged to extended position by means of a compression spring '26. The trigger member 8 extends through an aperture in the difierential head 2|, and through a leather backing 21 to a. position between the locking dogs 24, so as to hold the valve member I! in closed position, as shown in Fig. 1. The leather backing 21 is secured to the ends 23 of the plug member by screws 28. A compression spring 29 is provided in the valve member and bears against the differential head 2|, so as to urge the valve to closed position. As shown in Fig. 2, the plug member 22 is also provided with an aperture 30, which is open to atmosphere and permits access to the lower end of the valve member l'l. If the latter should happen to stick in open position, a small rod may be inserted into the opening 30 and the valve pressed to closed position, so that the trigger may be reengaged with the dogs 24. Thus it will be understood that the spring 29 is not necessary for operation of the device, but it is preferred touse it so that the ports [6 will be closed automatically after the cartridge is discharged, and will prevent material from getting into the casing and interfering with its subsequent operation.

. tained within the casing. When it is desired-to discharge the cartridge, an outward pull on the trigger member 8 will release the dogs 24, cause the valve member H to jump to the position shown in Fig. 3, and the high pressure gas will be discharged through angular lateral ports l8. Immediately after discharge, the spring 29 will cause the valve to return to closed'position, and the spring 26 will move the dogs 24 to a position where the trigger maybe returned to holding position. I

If desired, the trigger member and tubing may be connected to a long stroke air cylinder. When it is desired to operate the cartridge it is merely necessary to have the air cylinder pull on the 3 trigger member, and as the pulling continues during and after the discharge, the cartridge will be drawn clear or the broken material, so that no digging is necessary to have it available for the next operation. While it is preferred for saiety reasons to charge the cartridge after it has been installed in the hole to be blasted, it will be understood that the cartridge can be precharged, if desired;

The-foregoing detailed description is given for clearness of understanding only, and no unnecessary limitations should be understood therefrom, for some modifications will be obvious to those skilled in the art.

I claim:

1. A blasting cartridge comprising: a round hollow casing provided with laterally extending discharge ports; a sleeve-like valve in said casing adapted to close said ports and provided with a differential head whereby high gas pressure in the casing urges said valve to open position; expansible locking dogs in said casing for releasably holding the valve in closed position; a removable plug member in one end of the casing for receiving said dogs, and said plug member having an opening for permitting contact with said valve from outside of said casing; and a trigger member slidably mounted in the other end of the casing, extending through the diflerential head, and adapted to hold the dogs releasably in looking position.

2. A blasting cartridge comprising: a closed hollow casing provided with laterally extending discharge ports and adapted to receive an expansible gas under high pressure; valve means for closing said ports and urged to open position by gas pressure in said casing; lockingmeans in said casing for holding said valve means in closed position; and a trigger member extending through the casing to said locking means for said casing for holding said valve means in closed position; and a trigger member extending through the casing to said locking means for releasing the locking means at will; said locking means comprising a pair of expansible dogs which may be held in expanded locking position by the trigger member.

4. A blasting cartridge comprising: a closed hollow casing provided with laterally extendin discharge ports and adapted to receive an expansible gas under high pressure; valve means for closing said ports and urged to open position by gas pressure in said casing; locking means in said casing for holding said valve means in 4 closed position; and a trigger member extending through the'casing to said locking means for releasing the locking means at will; said looking means comprising a, pair of expansible dogs which may be held in expanded locking position by the trigger member, and a spring for urging said dogs to expanded position to facilitate reinsertion of said trigger member between them when the valve means is closed.

5. A blasting cartridge comprising: a closed hollow casing provided with laterally extending discharge ports and adapted to receive an expansible gas under high pressure; valve means for closing said ports and urged to openposition by gas pressure in said casing; locking means in said casing for holding saidvalve means in closed position; and a trigger member extending through the casing to said locking. means for releasing the locking means at will; said locking means comprising a pair of expansible dogs which may be held in expanded locking position by the trigger member, and said trigger member being provided with a stop within the casing to limit complete withdrawal from said casing.

FRANK H. ARMSTRONG.

REFERENCES CITED The following references are of record in the file of this patent:

Great Britain Dec. 15, 1930 

